Volvo V70XC parasitic drain and occasional no-start issues

2001downunderxc70 · Post by **2001downunderxc70** » 29 Nov 2018, 07:23

past 4 months have been a nightmare with the Volvo, looking for a bit of help diagnosing the problem(s).

Back in August I was getting low voltage problems and needed to jump start the Volvo despite constant driving. I ended up losing power queued in traffic on a main road (nightmare). Ended up replacing the battery, but the power drain problem was still there. Alternator is putting out ~13.2-14V, so I don't think it's an charging issue (although a leaking power steering pump sitting above the alternator makes me wonder). Meanwhile, there's a 0.3A parasitic draw that I can't seem to solve by pulling all the relays and fuses in any of the fuse boxes.

Cut to yesterday, and I the Volvo won't turn over. It clicks and starts to turn, but then the power cuts completely. I pulled the battery, slow-charged on 6Amps and same problem, even though the battery was reading 13.2V. Interesting thing is that the voltage at the positive battery terminal under the hood was 0.6-2V, whereas at the battery terminals it reads 13.2V. Pulling the negative lead resets the problem, and after 4-5 times the car now starts perfectly.

I'm stuck at a point where I don't trust driving with the kids in the car. Any ideas on what's causing the turning over issue? Could this be related to parasitic draw? I've read through the archives, but there seem to be a LOT of problems with the electrical system on the V70XC that could be related to this...

Post by **RickHaleParker** » 30 Nov 2018, 06:37

Inspect the battery cable from the battery to under the hood for partly shorts, (thin insulation ect), poor connections and corrosion.

If water and road salt gets under the insulation there maybe corrosion where you cannot see it. This tends to happen near the ends of the cables but it can happen anywhere the cable insulation is compromised.

2001downunderxc70 · Post by **2001downunderxc70** » 30 Nov 2018, 06:45

Ends of the cables look clean as a whistle. It never stops below 60F here and there’s no salt corrosion. Any way of testing this with a multimeter?

Post by **RickHaleParker** » 30 Nov 2018, 06:47

You got leads long enough to run from the battery to under the hood? In other words measure the voltage drop along the length of the cable.

2001downunderxc70 · Post by **2001downunderxc70** » 30 Nov 2018, 06:49

I don’t, but I might be able to rig up something... failing that, and if they pass a visual inspection, any ideas on where else to look?

Post by **RickHaleParker** » 30 Nov 2018, 06:58

Based on my interpretation of your description, I suspect something going on in the battery cable, it could be on the positive side or the negative side. So bad grounds would be the another thing to look for.

Post by **oragex** » 30 Nov 2018, 09:12

Do you have light at the car plate? In no, undo the trunk door cover and disconnect the cable to the trunk switch and plate light (use the key to open the trunk first, see if it works to open it)

To test the battery, after driving the car, shut off the engine and wait at least 30 minutes for the voltage to stabilize. I prefer then disconnecting the battery and measure it, because anything that's on in the car - even just the trunk lights - will drop the voltage reading. A battery would be between 12.0v (almost fully discharged) and 12.7v (or perhaps 12.8v in a hot summer day) when fully charged. Usually a fresh battery stays always at full charge voltage even when driving the car.

The alternator should put 13.7v if the battery is fully charged, and about 14.5v if the battery needs to be charged.

reverend · Post by **reverend** » 30 Nov 2018, 12:20

Test the battery. If you have a few bad plates in it, it can still give you 13 volts but once you demand some amps, it 'croaks'.

2001downunderxc70 · Post by **2001downunderxc70** » 01 Dec 2018, 03:38

oragex wrote: ↑30 Nov 2018, 09:12 Do you have light at the car plate? In no, undo the trunk door cover and disconnect the cable to the trunk switch and plate light (use the key to open the trunk first, see if it works to open it)

Huh interesting. What's the rational behind this one? Would a blown light cause a battery drain?

2001downunderxc70 · Post by **2001downunderxc70** » 01 Dec 2018, 03:40

reverend wrote: ↑30 Nov 2018, 12:20 Test the battery. If you have a few bad plates in it, it can still give you 13 volts but once you demand some amps, it 'croaks'.

Battery is new as of 2 weeks ago, and i'd had it on a 6A charger before the no-start issue happened (reading 13.2V at the battery). Starts fine now, but i'm still not convinced enough to drive it. At this rate i'll drop it off at the mechanic midweek, as I don't have cables long enough to test for a voltage drop between the front and back (really wish they'd just left the battery under the hood).